The New Zealand dollar fell below 70 US cents to the lowest since late July as the greenback extended its rally on speculation US president-elect Donald Trump will enact policies that stoke economic growth.
The local currency traded at 70.01 US cents, having earlier dipped to 69.93 cents, from 70.09 cents in late New York trading on Friday. The trade-weighted index fell to 77.17 from 77.23.
The US dollar index rose 0.5 per cent to the highest since March 2003 and has gained 3.6 per cent since the US presidential election on November 8.
Mr Trump has vowed to embark on a massive infrastructure spending programme and plans to slash corporate tax among moves investors say will stoke economic growth and inflation, and drive up interest rates. The yield on the US benchmark 10-year Treasury bond rose to 2.34 percent on Friday, the highest in more than a year.
"The USD continued to grind higher on Friday, setting fresh milestones in the process," said BNZ's Jason Wong.
"There was little news flow to drive markets - investors were still adjusting positions to reflect the new Trump world of potentially easier fiscal policy and tighter monetary policy".
Investors are awaiting the release this week of the minutes from the latest Federal Reserve policy meeting in a week shortened in the US by the Thanksgiving holiday, which will see its markets closed on Thursday.
Mr Wong said the kiwi dollar hasn't fallen as sharply against the greenback as some other currencies because of evidence the New Zealand economy is growing at a respectable pace, including Fonterra's decision last week to raise its milk payout for farmers.
The kiwi slipped to 77.64 yen from 77.70 yen on Friday in New York, fell to 4.8225 yuan from 4.8266 yuan, traded at 56.75 British pence from 56.73 pence, dipped to 66.02 euro cents from 66.16 cents and was up to 95.56 Australian cents from 95.50 cents.